I don't know why the boat builders put an open cell foam in there, maybe because it is less expensive than a closed cell product, or maybe just to meet USC requirements, but you are sure right about it absorbing water, it will support the flotation factor, but not for extended periods of exposure with water, that time depending on elements and conditions. The way the foam is installed in the boats add No rigidity to the hull, it rattles around in there causing noise and makes it's own little dust pile to hold water when it does come in contact with it, retaining moisture that will inhance rot to any wood in those enclosed areas.
Most reputable boat makers today, use a two part foam liquid that generates styrene bubbles that expand, creating closed cells that maintain their flexability after curing, the mixture is poured, or injected into these enclosed areas and not only create a dynamic flotation source, but it adds a substantial reinforcement to the hull. All the two part mixtures do not create closed cells, like the one used to make the little "logs" you are referring to, it is not a polystyrene product, the tiny little bubbles that makes it expand become rigid when cured, and will repel water, but not water proof. All that said, those little foam logs were put there to prevent your boat from sinking alright, and would as a result save lives, and they worked for that purpose only, but they will, as you know, absorb the water during continuous exposure.
I injected those areas in my boat with a closed cell foam that is actually designed for household use, to seal structural cracks, window and door frames, and is available at most hardware stores, it's called "Great Stuff" I do Not use the little tube that comes with the can to direct it's use, I drill 1/4 inch holes where I want to inject it, stick the orfice of the can directly into the drilled hole and inject it, it will empty the can of it's contents in about 10 seconds that way, allowing maximum expantion and rigidity. I have been using this "Stuff" for several years with good results.
what was the purpose of the hull foam other than it just seems to soak up every bit of water that comes in contact with it and if you ever flipped your boat it might float?
-- Edited by goofy4glass on Friday 5th of February 2010 10:52:39 PM
